%0 Journal Article
%A Alan Filipin
%T An irregular $D(4)$-quadruple cannot be
 extended to a quintuple
%J Acta Arithmetica
%D 2009
%P 167-176
%V 136
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/articles/10.4064/aa136-2-5/
%R 10.4064/aa136-2-5
%G en
%F 10_4064_aa136_2_5